3,798 research outputs found
Carbon Emission Flow in Networks
As the human population increases and production expands, energy demand and anthropogenic carbon emission rates have been growing rapidly, and the need to decrease carbon emission levels has drawn increasing attention. The link between energy production and consumption has required the large-scale transport of energy within energy transmission networks. Within this energy flow, there is a virtual circulation of carbon emissions. To understand this circulation and account for the relationship between energy consumption and carbon emissions, this paper introduces the concept of “carbon emission flow in networks” and establishes a method to calculate carbon emission flow in networks. Using an actual analysis of China's energy pattern, the authors discuss the significance of this new concept, not only as a feasible approach but also as an innovative theoretical perspective
Socioeconomic Drivers of Greenhouse Gas Emissions in the United States
Existing studies examined the U.S.’s direct GHG emitters and final consumers driving upstream GHG emissions, but overlooked the U.S.’s primary suppliers enabling downstream GHG emissions and relative contributions of socioeconomic factors to GHG emission changes from the supply side. This study investigates GHG emissions of sectors in the U.S. from production-based (direct emissions), consumption-based (upstream emissions driven by final consumption of products), and income-based (downstream emissions enabled by primary inputs of sectors) viewpoints. We also quantify relative contributions of socioeconomic factors to the US’s GHG emission changes during 1995–2009 from both the consumption and supply sides, using structural decomposition analysis (SDA). Results show that income-based method can identify new critical sectors leading to GHG emissions (e.g., Renting of Machinery & Equipment and Other Business Activities and Financial Intermediation sectors) which are unidentifiable by production-based and consumption-based methods. Moreover, the supply side SDA reveals new factors for GHG emission changes: mainly production output structure representing product allocation pattern and primary input structure indicating sectoral shares in primary inputs. In addition to production-side and consumption-side GHG reduction measures, the U.S. should also pay attention to supply side measures such as influencing the behaviors of product allocation and primary inputs
Evaluating Depressive Symptoms in Schizophrenia: A Psychometric Comparison of the Calgary Depression Scale for Schizophrenia and the Hamilton Depression Rating Scale
Background: The aim of this study was to compare two measures of depression in patients with schizophrenia and schizophrenia spectrum disorder, including patients with delusional and schizoaffective disorder, to conclude implications for their application. Sampling and Methods: A total of 278 patients were assessed using the Calgary Depression Scale for Schizophrenia (CDSS) and the Hamilton Depression Rating Scale (HAMD-17). The Positive and Negative Syndrome Scale (PANSS) was also applied. At admission and discharge, a principal component analysis was performed with each depression scale. The two depression rating scales were furthermore compared using correlation and regression analyses. Results: Three factors were revealed for the CDSS and HAMD-17 factor component analysis. A very similar item loading was found for the CDSS at admission and discharge, whereas results of the loadings of the HAMD-17 items were less stable. The first two factors of the CDSS revealed correlations with positive, negative and general psychopathology. In contrast, multiple significant correlations were found for the HAMD-17 factors and the PANSS sub-scores. Multiple regression analyses demonstrated that the HAMD-17 accounted more for the positive and negative symptom domains than the CDSS. Conclusions:The present results suggest that compared to the HAMD-17, the CDSS is a more specific instrument to measure depressive symptoms in schizophrenia and schizophrenia spectrum disorder, especially in acutely ill patients. Copyright (c) 2012 S. Karger AG, Base
Very high energy particle acceleration powered by the jets of the microquasar SS 433
SS 433 is a binary system containing a supergiant star that is overflowing
its Roche lobe with matter accreting onto a compact object (either a black hole
or neutron star). Two jets of ionized matter with a bulk velocity of
extend from the binary, perpendicular to the line of sight, and
terminate inside W50, a supernova remnant that is being distorted by the jets.
SS 433 differs from other microquasars in that the accretion is believed to be
super-Eddington, and the luminosity of the system is erg
s. The lobes of W50 in which the jets terminate, about 40 pc from the
central source, are expected to accelerate charged particles, and indeed radio
and X-ray emission consistent with electron synchrotron emission in a magnetic
field have been observed. At higher energies (>100 GeV), the particle fluxes of
rays from X-ray hotspots around SS 433 have been reported as flux
upper limits. In this energy regime, it has been unclear whether the emission
is dominated by electrons that are interacting with photons from the cosmic
microwave background through inverse-Compton scattering or by protons
interacting with the ambient gas. Here we report TeV -ray observations
of the SS 433/W50 system where the lobes are spatially resolved. The TeV
emission is localized to structures in the lobes, far from the center of the
system where the jets are formed. We have measured photon energies of at least
25 TeV, and these are certainly not Doppler boosted, because of the viewing
geometry. We conclude that the emission from radio to TeV energies is
consistent with a single population of electrons with energies extending to at
least hundreds of TeV in a magnetic field of ~micro-Gauss.Comment: Preprint version of Nature paper. Contacts: S. BenZvi, B. Dingus, K.
Fang, C.D. Rho , H. Zhang, H. Zho
- …